The NYC subway system's unlimited-ride MetroCard turned ten years old this month.
"I think it's absolutely changed travel habits in the New York region, and it's been a boon for the economy as well," said Andrew Albert, who represents transit riders on the board of the Metropolitan Transportation Authority. "Where once you might have used it more sparingly because you had a finite number of trips, you're more likely to take a trip during your lunch break, go shopping perhaps or go to dinner somewhere," he said.
On average, unlimited-ride MetroCard users take 56 trips per month (~$1.45 per trip), although some take many more or less. (via buzzfeed)
Update: Mike Frumin notes that the Times excluded from their graph an important piece of information: the break-even point of the 30-day MetroCard. I used to get a monthly card but now pay by the ride because I don't take the subway everyday anymore and would therefore find myself in Frumin's "losing $$$$$" zone.